Recommendation of RILEM Technical Committee 250-CSM: Test method for Textile Reinforced Mortar to substrate bond characterization

Textile Reinforced Mortar (TRM), also known as Fabric Reinforced Mortar or Fabric Reinforced Cementitious Matrix, composites are an emerging technology for the external repair and strengthening of existing structures. For most applications, the effectiveness of the TRM reinforcement relies on its bond performance. This recommendation identifies the best practice to characterize the bond behaviour of TRM. A shear bond test method is proposed to determine the peak axial stress (associated with the maximum load that can be transferred from the structural member to the externally bonded TRM reinforcement), the stress–slip relationship and the failure mode that controls the TRM-to-substrate load transfer capacity. Guidelines on specimen manufacturing, experimental setup, test execution, and determination of test results are provided.     

AAOP-based dynamically reconfigurable monitoring system

A key aspect of resource management is efficient and effective deployment of available resources whenever needed. The issue typically covers two areas: monitoring of resources used by software systems and managing the consumption of resources. A key aspect of each monitoring system is its reconfigurability – the ability of a system to limit the number of resources monitored at a given time to those that are really necessary at any particular moment. The authors of this article propose a fully dynamic and reconfigurable monitoring system based on the concept of Adaptable Aspect-Oriented Programming (AAOP) in which a set of AOP aspects is used to run an application in a manner specified by the adaptability strategy. The model can be used to implement systems that are able to monitor an application and its execution environment and perform actions such as changing the current set of resource management constraints applied to an application if the application/environment conditions change. Any aspect that implements a predefined interface may be used by the AAOP-based monitoring system as a source of information. The system utilizes the concept of dynamic AOP, meaning that the aspects (which are sources of information) may be dynamically enabled/disabled.     

Analysis and modelling of traffic produced by adaptive HTTP-based video

The increase of HTTP-based video popularity causes that broadband and Internet service providers’ links transmit mainly multimedia content. Network planning, traffic engineering or congestion control requires an understanding of the statistical properties of network traffic; therefore, it is desirable to investigate the characteristic of traffic traces generated by systems which employ adaptive bit-rate streaming. Our first contribution is an investigation of traffic originating from 120 client-server pairs, situated in an emulated content distribution network, and multiplexed onto a single network link. We show that the structure of the traffic is distinct from the structure generated by the first and second generation of HTTP video systems, and furthermore, not similar to the structure of general Internet traffic. The obtained traffic exhibits negative and positive correlations, anti-persistence, and its distribution function is skewed to the right. Our second contribution is an approximation of the traffic by ARIMA/FARIMA processes blue and artificial neural networks. As we show, the obtained traffic models are able to enhance the performance of an adaptive streaming algorithm.     

Complex modification effect of linseed cake as an agricultural waste filler used in high density polyethylene composites

Linseed cake (LC) is a by-product of agricultural industry which does not have any large-scale industrial applications. The possibilities of its utilization as filler with plasticizing ability for high density polyethylene (HDPE)-based composites have been investigated. Composites containing 5, 10, 20 and 30 wt% of the waste filler have been prepared using a melt mixing method. The influence of the LC on the mechanical and thermomechanical properties of the composites, as well as their water absorption and morphology, have been evaluated by the following methods: static tensile test, impact strength assessment using Dynstat method, hardness measurements, differential scanning calorimetry, dynamic mechanical thermal analysis, scanning electron microscopy observations, measurements of Vicat’s softening temperature and water uptake test. Application of different measuring techniques allows for describing complex modification effects of the composites’ properties changes induced by the presence of lignocellulosic filler with high oil content. The results of the study proved a pronounced influence of LC on high density polyethylene-based composites, especially a plasticizing effect of crude linseed oil contained by the waste filler particles. LC also has been assumed to affect the polymeric matrix crystallization process. It was found that complex modification of polyethylene results from simultaneously occurring different phenomena including: plasticization of the HDPE by linseed oil, improved crystallinity of the semicrystalline matrix, presence of the rigid lignocellulosic particles dispersed in polymer and accumulation of the oil in the interfacial regions.     

A thermo-mechanical machining method for improving the accuracy and stability of the geometric shape of long low-rigidity shafts

Journal of Intelligent Manufacturing - The article presents a new thermo-mechanical machining method for the manufacture of long low-rigidity shafts which combines straightening and heat treatment...     

The Impact of Linseed Oil Lipids on the Physical Properties of Corn Crisps and the Possibility of Obtaining Crisps Enriched with n‐3 Fatty Acids

Linseed oil, also known as flaxseed oil, is obtained from the dried, ripened seeds of the flax plant (Linum usitatissimum). The oil is obtained by pressing, sometimes followed by solvent extraction supported by a refining process. Linseed oil is an edible oil that is in demand as a nutritional supplement, as a source of α‐linolenic acid an n‐3 fatty acid. The aim of this work was to investigate: (1) the influence of the corn crisp extrusion process on the degradation of fatty acids in linseed oil (LO) and some preparations obtained from the linseed oil such as ethyl ester (EE) and free fatty acids (FFA) added to the corn in order to increase the nutritional value of the crisps, (2) influence of the oil and two fatty preparations obtained from it on the quality of corn crisps, (3) interaction of the lipid fraction with starch. The extrusion process did not degrade the fatty acids significantly. Expansion ratio obtained in the corn crisp extrusion process decreased from 620 % down to 153 %, the size of pores/thickness of the starch–protein walls forming the structure of the extruded product decreased from 10 μm down to 4 μm, the hardness of the crisps increased from 20 to 75 N, and number of lipid–starch complexes increased with rising polarity of the lipid fraction. FFA were complexed mostly by starch (about 90 %), to a lesser degree by EE (about 60 %) and to the least extent by triacylglycerols (about 10 %). The studies performed under industrial conditions using the single screw extruder for the production of corn crisps with the application of standard parameters of the extrusion process indicated that the addition of a mass of 5 % of the various lipids (triacylglycerols of linseed oil, ethyl esters and fatty acids obtained from linseed oil) to corn grits prior to the extrusion process significantly affect the quality of corn crisps.     

Nonisothermal crystallization of highly‐filled polyolefin/calcium carbonate composites

Nonisothermal crystallization kinetics of highly‐filled polyolefin composites was studied by means of differential scanning calorimetry (DSC). Two types of commercial calcium carbonate based fillers (modified with stearic acid and nonmodified one) were used for our investigations. In order to evaluate the crystallization kinetics changes of composites, the Avrami theory modified by Jeziorny was used. Validity of mineral fillers modification with stearic acid has been proved by thermal analysis. Because of the suppression of the heterogeneous nucleation effect resulting from calcium carbonate with stearic acid modification, an increase in the processability of highly‐filled polyolefin cast films might occur. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41201.     

Correction for ambiguous solutions in factor analysis using a penalized least squares objective

Factor analysis is a powerful tool used for the analysis of dynamic studies. One of the major drawbacks of factor analysis of dynamic structures (FADS) is that the solution is not mathematically unique when only nonnegativity constraints are used to determine factors and factor coefficients. In this paper, a method to correct for ambiguous FADS solutions has been developed. A nonambiguous solution (to within certain scaling factors) is obtained by constructing and minimizing a new objective function. The most common objective function consists of a least squares term that when minimized with nonnegativity constraints, forces agreement between the applied factor model and the measured data. In our method, this objective function is modified by adding a term that penalizes multiple components in the images of the factor coefficients. Due to nonuniqueness effects, these factor coefficients consist of more than one physiological component. The technique was tested on computer simulations, an experimental canine cardiac study using 99mTc-teboroxime, and a patient planar 99mTc-MAG3 renal study. The results show that the technique works well in comparison to the truth in computer simulations and to region of interest (ROI) measurements in the experimental studies.